Regular Marijuana Use by Teens Continues to Be a Concern

NIDA's 2012 Monitoring the Future Survey Shows Rates Stable or Down for Most Drugs

BETHESDA, MD--(Marketwire - Dec 19, 2012) - Continued high use of marijuana by the nation's eighth, 10th and 12th graders combined with a drop in perceptions of its potential harms was revealed by this year's Monitoring the Future survey, an annual survey of eighth, 10th, and 12th-graders conducted by researchers at the University of Michigan. The survey was carried out in classrooms around the country earlier this year, under a grant from the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health.

The 2012 survey shows that 6.5 percent of high school seniors smoke marijuana daily, up from 5.1 percent five years ago. Nearly 23 percent say they smoked it in the month prior to the survey, and just over 36 percent say they smoked within the previous year. For 10th graders, 3.5 percent said they use marijuana daily, with 17 percent reporting past month use and 28 percent reporting use in the past year. The use escalates after eighth grade, when only 1.1 percent reported daily use, and 6.5 percent reported past month use. More than 11 percent of eighth graders said they used marijuana in the past year.

The Monitoring the Future survey also showed that teens' perception of marijuana's harmfulness is down, which can signal future increases in use. Only 41.7 percent of eighth graders see occasional use of marijuana as harmful; 66.9 percent see regular use as harmful. Both rates are at the lowest since the survey began tracking risk perception for this age group in 1991. As teens get older, their perception of risk diminishes. Only 20.6 percent of 12th graders see occasional use as harmful (the lowest since 1983), and 44.1 percent see regular use as harmful, the lowest since 1979.

A 38-year NIH-funded study, published this year in the Proceedings of the National Academy of Sciences, showed that people who used cannabis heavily in their teens and continued through adulthood showed a significant drop in IQ between the ages of 13 and 38 -- an average of eight points for those who met criteria for cannabis dependence. Those who used marijuana heavily before age 18 (when the brain is still developing) showed impaired mental abilities even after they quit taking the drug. CONTINUED...